The program, called “Future Attribute Screening Technology,” or FAST, works as a combination of custom software and crowd-monitoring body sensors, strategically placed at airports, U.S. border crossings, and other public, high-security areas.

In simulated scenarios, the DHS says FAST is accurate in detecting suspicious behavior in almost four out of five cases. One such trial, run recently at an equestrian ranch in Maryland, paid more than 140 participants $150 to walk through FAST’s sensor array; a handful of the participants were given instructions to act shifty, evasive, deceptive, or even hostile. FAST had an effective accuracy rate of “about [78 percent] on mal-intent detection, and [80 percent] on deception,” according to spokesman John Verrico.

“We're still very early on in this research, but it is looking very promising,” he said.

Individuals detected as suspicious by FAST will be pulled aside for light questioning by security staff. Information processed by the system will never be matched with names, said Verrico, and it will only be used to help security screeners decide whom to question. After that, data from FAST is discarded.

DHS researchers are designing FAST with mobility in mind, and over the long term would like to roll out portable vehicles for use in concerts, sporting events, and other public gatherings: once the technology is perfected, writes New Scientist’s Short Sharp Science blog, FAST trucks could be as common a sighting at public gatherings as “mobile toilets and catering trucks.”

The Electronic Privacy Information Center’s John Verdi said FAST is “substantially more invasive than screening in airports,” calling it a “medical exam” that the government has no right to conduct. Critics are concerned that the program could reveal physical conditions like heart murmurs, breathing problems, and high stress levels – a blatant privacy invasion – as well as set off false alarms.

FAST appears to be yet another aspect of the U.S. – as well as the rest of the world’s – governments’ growing fascination with biometric data on citizens: the FBI’s “Next Generation Identification” system, currently still in development, seeks to catalogue almost every major identifying characteristic about the U.S. criminal population, including fingerprints, retinal prints, and tattoo/scar markings.

Like the NGI, FAST is still under development and has several years left before it is ready for widespread, public usage – if it even makes it that far. The program is in its second year in development, and has three left to go. USA Today notes that the Transportation Security Administration already has more than 2,000 human screeners doing the same thing – essentially paving the way for their replacement and more widespread deployment by FAST.

"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates